More specifically, it's translucent materials working with reflection probes. Slightly more generally, this means forward rendered materials working with reflection probes. Ideally, we make the forward materials utilize the exact same math that our PBR deferred materials do, for consistency, but the main focus is probes, because normally speaking, the only forward rendering materials used in deferred are translucent materials, like glass.

When I get the math shored up, the glass'll reflect the nearest probes' reflections - parallax corrected just like on the deferred PBR surfaces - and it'll look really nice. Following similar math to the regular PBR materials, metalness infers towards how reflective it is vs how much the diffuse material contributes.

Pleasingly, also takes the normals into account, so doing warped glass, or the natural distortion of plate glass is super easy to do as well and should look great in the end.

Another bit of an update, finally made headway on the transparency reflections.

You can see them in action below:

Some bits left to do with probes yet, namely having it blend between a few of the most relevent probes on forward materials(like the above translucency), as well as better controlling the fallbacks and doing cleanup and the like. But they're getting pretty close to being done.

Also, we've been working to dial in the PBR math. There's been a few squirrely bits that have been a bit off. Timmy rigged up a small self-contained tool to visualize PBR art so we can better figure out what's off, and I think he's pretty much got the math down, given how the results are looking:

From there, we can port over the differences to the math and PBR is pretty danged close to being ready.

Nice work jeff the transparency stuff is coming along really well. I will get to work this week bringing in the other pbr stuff i was doing above, so hopefully we should be really cooking with gas with it all combined.